Electron beam freeform fabrication (EBF3) is an emerging manufacturing deposition process in which an electron beam is used in conjunction with a wire feed to progressively deposit material onto a substrate in a layered manner. The electron beam is translated with respect to a surface of the substrate while the wire is melted and fed into a molten pool. In an EBF3 process, a design drawing of a three-dimensional (3D) object may be sliced into different layers as a preparatory step, with the electron beam tracing each of the various layers within a vacuum chamber. The layers ultimately cool into a desired complex or 3D shape.
Currently, EBF3 processing uses limited closed-loop motor control on each of the individual positioning, electron beam, and wire feeder axes to ensure that each axis is driving to the requested value, e.g., when a signal of “move X axis 4.000 inches at a speed of 10.0 inches/min” is sent to a motor driver, a feedback loop tracks the speed and location to verify that motion occurs as programmed. However, real-time sensing or feedback is lacking on the actual deposition process. Anomalies are common, e.g., changing chemistry of the resulting deposit, wire position control, gradual increase in temperature affecting the size and shape of the molten pool and resulting deposit, over or under build of a target height due to an improperly programmed height, etc. Therefore, process reproducibility issues may result, along with difficulty in certifying EBF3-fabricated components.